A large number of organic synthetic reactions using a transition metal complex as a catalyst have hitherto been developed and made use of for various purposes. In particular, many reports have been made on enantioselective catalysts used for enantioselective synthetic reactions, such as enantioselective hydrogenation and enantioselective isomerization. Among them, metal complexes in which an optically active tertiary phosphine compound is coordinated to metallic rhodium or ruthenium are well known as catalysts for enantioselective hydrogenation reactions.
For example, a rhodium-phosphine complex using 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (hereinafter abbreviated as BINAP) as a ligand is disclosed in JP-A55-61937 (the term "JP-A" as used herein means an "unexamined published Japanese patent application").
With regard to ruthenium, ruthenium complexes obtained by using BINAP or 2,2'-bis(di-p-tolylphosphino)-1,1'-binaphthyl (hereinafter abbreviated as Tol-BINAP) as a ligand, such as Ru.sub.2 Cl.sub.4 (BINAP).sub.2 NEt.sub.3 (wherein Et represents an ethyl group) and Ru.sub.2 Cl.sub.4 (Tol-BINAP).sub.2 NEt.sub.3 have been reported (Ikariya et al., J. Chem. Soc., Chem. Commun., p. 922 (1985)). Also, Ru(O.sub.2 CR.sup.4).sub.2 (BINAP) and Ru(O.sub.2 CR.sup.4).sub.2 (Tol-BINAP) (wherein R.sup.4 represents a lower alkyl group or a lower alkyl-substituted phenyl group) have been disclosed in JP-A-62-265293; and [RuH.sub.l (R.sup.5 -BINAP).sub.m ]Z.sub.n (wherein R.sup.5 represents a hydrogen atom or a methyl group; Z represents ClO.sub.4, BF.sub.4, or PF.sub.6 ; when l is 0, then m represents 1, and n represents 2; and when l is 1, then m represents 2, and n represents 1) has been disclosed in JP-A-63-41487. However, these ruthenium complexes were complicated in their preparation and had such disadvantages as low yield and poor stability.
Furthermore, JP-A-2-191289 has reported [RuX.sub.l (S).sub.m (R.sup.6 -BINAP)]Y.sub.n (wherein R.sup.6 represents a hydrogen atom or a methyl group; X represents a halogen atom; S represents benzene which may be substituted or acetonitrile; Y represents a halogen atom, ClO.sub.4, PF.sub.6, BPh.sub.4 (wherein Ph represents a phenyl group), or BF.sub.4 ; in the case where S is benzene which may be substituted, l is 1, m is 1, and n is 1; and in the case where S is acetonitrile, when l is 1, then m is 2, and n is 1, and when l is 0, then m is 4, and n is 2). However, even when these phosphine complexes are used, there were sometimes problems in their practical applications on an industrial scale, such as insufficiency in catalytic activity, duration, and enantioselectivity depending on the reactions and reaction substrates.
On the other hand, optically active 1-substituted-1,3-propanediols are useful intermediates in enantioselective synthesis for the production of pharmaceuticals, liquid crystal compounds, and natural products. Among these, as a production method of optically active 1-phenyl-1,3-propanediol which is useful as an intermediate of pharmaceuticals such as fluoxetine and tomoxetine, a method in which cinnamyl alcohol is subjected to enantioselective epoxidation to obtain optically active epoxycinnamyl alcohol, which is then reduced by Red-Al (sodium bis(2-methoxyethoxy)aluminum hydride) is reported (Y. Gao, et al., J. Org. Chem., 53, pp. 4081-4084 (1988)). In the above method, however, not only Red-Al which is difficult to handle is employed, but products having a satisfactorily high optical purity cannot be obtained.